6,565 research outputs found
From 3D Models to 3D Prints: an Overview of the Processing Pipeline
Due to the wide diffusion of 3D printing technologies, geometric algorithms
for Additive Manufacturing are being invented at an impressive speed. Each
single step, in particular along the Process Planning pipeline, can now count
on dozens of methods that prepare the 3D model for fabrication, while analysing
and optimizing geometry and machine instructions for various objectives. This
report provides a classification of this huge state of the art, and elicits the
relation between each single algorithm and a list of desirable objectives
during Process Planning. The objectives themselves are listed and discussed,
along with possible needs for tradeoffs. Additive Manufacturing technologies
are broadly categorized to explicitly relate classes of devices and supported
features. Finally, this report offers an analysis of the state of the art while
discussing open and challenging problems from both an academic and an
industrial perspective.Comment: European Union (EU); Horizon 2020; H2020-FoF-2015; RIA - Research and
Innovation action; Grant agreement N. 68044
Recent Advances in Graph Partitioning
We survey recent trends in practical algorithms for balanced graph
partitioning together with applications and future research directions
A GPU-enabled implicit Finite Volume solver for the ideal two-fluid plasma model on unstructured grids
This paper describes the main features of a pioneering unsteady solver for
simulating ideal two-fluid plasmas on unstructured grids, taking profit of
GPGPU (General-purpose computing on graphics processing units). The code, which
has been implemented within the open source COOLFluiD platform, is implicit,
second-order in time and space, relying upon a Finite Volume method for the
spatial discretization and a three-point backward Euler for the time
integration. In particular, the convective fluxes are computed by a multi-fluid
version of the AUSM+up scheme for the plasma equations, in combination with a
modified Rusanov scheme with tunable dissipation for the Maxwell equations.
Source terms are integrated with a one-point rule, using the cell-centered
value. Some critical aspects of the porting to GPU's are discussed, as well as
the performance of two open source linear system solvers (i.e. PETSc,
PARALUTION). The code design allows for computing both flux and source terms on
the GPU along with their Jacobian, giving a noticeable decrease in the
computational time in comparison with the original CPU-based solver. The code
has been tested in a wide range of mesh sizes and in three different systems,
each one with a different GPU. The increased performance (up to 14x) is
demonstrated in two representative 2D benchmarks: propagation of circularly
polarized waves and the more challenging Geospace Environmental Modeling (GEM)
magnetic reconnection challenge.Comment: 22 pages, 7 figure
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